The present invention relates to a defect detecting apparatus which can effectively perform inspections and observations on a surface of a sample such as an evaluation on the structure thereof, an observation in an enlarged view, and an evaluation on materials, an electric conduction state and the like on the surface to detect defects on high density patterns having, for example, a minimum line width of 0.15 μm or less with high accuracy and high reliability, and a device manufacturing method which relies on the defect detecting apparatus to inspect patterns intermediate of a semiconductor device manufacturing process.
In the present invention, the word “mapping” as referred to in the mapping optics means that an electron beam is irradiated on a field of view ranging at least one dimension to form an image of the field of view. Description of the Related Art:
Conventionally, a known testing apparatus detects possible defects on a wafer or a substrate by irradiating the surface of the substrate with a scanning electron beam, obtaining wafer image data from detected secondary electrons emitted from the substrate, and comparing the image data of each die on the wafer with that of adjacent dies.
In a conventional SEM-based system as described above, and a system which simultaneously illuminates a wide area, such as a mapping projection system, an insulating material on the substrate is charged as a substrate under inspection is irradiated with an electron beam. However, if the substrate is overcharged, image data from detected secondary electrons emitted from the substrate undergoes distortions which cause the system to detect false defects (falsely reported defects), to produce obscure images, and to suffer from damages such as dielectric breakdown.